Enhancing 3G ETA solar cells with novel Bi2Se3 nanoparticles synthesized on TiO2: Impact of immersion cycles on PEC performance

The development of unexposed layer heterostructures by integrating metal chalcogenide semiconductors with metal oxide arrays offers a promising approach to enhance surface area, expand optical response, and improve charge kinetics key factors for achieving high-performance photoconversion devices. In this study, we introduce a facile, room-temperature chemical method using successive ionic layer adsorption and reaction (SILAR) to deposit Bi₂Se₃ nanoparticles onto spin-coated TiO₂ arrays. We systematically explore the structural, optical, and surface morphological properties of the resulting TiO₂/Bi₂Se₃ heterostructures. Our findings reveal that the thin layer of Bi₂Se₃ nanoparticles uniformly coats the porous TiO₂, extending its optical response into the visible region. We also examine the charge kinetics and solar cell performance of devices constructed with an fluorine doped tin oxide (FTO)/TiO₂/Bi₂Se₃/polysulfide/carbon-coated FTO sandwich-type architecture. Through comparative analysis, we assess the initial characterizations, charge kinetics, and photovoltaic performance of the TiO₂/Bi₂Se₃ heterostructures across different SILAR cycles. Our results demonstrate a significant enhancement in photocurrent for the bilayer TiO₂/Bi₂Se₃ architecture (0.55 mA/cm²) compared to bare TiO₂ (0.041 mA/cm²). This research highlights the potential of the proposed heterostructure to improve the efficiency of energy conversion devices.